Surface treatment device

Abstract: The present invention relates to a surface treatment device for performing a surface treatment such as plating by feeding a treating liquid to an inside peripheral surface of a cylindrical portion of a work wherein a treating liquid feeding path is connected to a treating liquid feeding pipe for feeding the treating liquid from a tank wherein a treating liquid discharging path is connected to a treating liquid recovering pipe for collecting the treating liquid in said tank and that a sucking device is provided in the treating liquid recovering pipe for sucking the treating liquid.

Description: This invention relates to a surface treatment device for carrying out a surface treating method applied for a plating treatment, a pretreatment therefor, etc. in the plating of an inside periphery of a cylindrical portion of a work, such as a cylinder block of an engine, and especially for subjecting a surface to be treated to a high speed surface treatment while allowing a treating liquid to flow. A variety of techniques concerning a surface treatment such as plating of a surface to be treated of a work or a degreasing treatment as a pretreatment therefor have been hitherto known. For example, a method is generally known in which a work is immersed in a treating liquid contained in a tank for performing plating, etc. This method, however, requires a long treatment time and is not efficient. Additionally, this method requires high costs for the treatment of a waste liquid, etc. Thus, a method is proposed in which a treating liquid is allowed to flow relative to a surface to be treated of a work with a view toward improving the treating efficiency and realising a high speed treatment (DE 39 37 763, ER 2 685 924 A1). For example, Japanese Examined Patent Publication No. 1-52480 discloses a surface treatment device applied for the degreasing treatment in chrome plating of an inside surface of cylinder of an engine, in which each of the openings at both ends of the engine cylinder is plugged with a plug through a sealing material. One of the plugs is provided with a treating liquid feed passage while the other plug is provided with a treating liquid return passage. The both passages are in fluid communication with the inside space of the cylinder. A tank for the treating liquid, a pump, valves, etc. are connected to a piping system including the above passages. In the thus constructed device, the treating liquid is recirculated with a pump through the treating liquid feed passage--inside of the cylinder--treating liquid return passage--tank. The flow of the treating liquid through the inside of the cylinder permits a high speed treatment of the inside the surface the cylinder. While the above publication mainly describes a case in which the device is applied for a degreasing step, it is also effective to allow a plating liquid to flow relative to a surface to be treated of a work in a plating step. Especially when an inside peripheral surface of a cylindrical portion of a cylinder or the like is subjected to plating, a high speed plating treatment can be accomplished by applying a voltage with an increased current density to electrodes disposed in the cylindrical portion while permitting a plating liquid to flow in the state where the opened portions are sealed. In the device shown in the above publication, the cylinder is set in such a state that the open portions on both sides of the cylinder is oriented in a horizontal position. Thus, an end face of each of the opened portions of is sealed by applying and pressing a sealing member and a plug. In such a state, the treating liquid is fed from one side of the cylinder by the action of a pump while discharging the treating liquid from the other side thereof. With such a construction, however, it is difficult to completely prevent the leakage of the treating liquid from the inside of the cylinder, when the one side of the cylindrical portion has parts with different sizes such as walls constituting a crank chamber as in a cylinder block of ordinary automobiles. Namely, because the cylinder block of an automobile generally has a structure in which a portion having a plurality of cylinders is integrally connected to a wall defining a skirt-like crank chamber connected to one side (underside in use) of the cylinder-disposed portion and because the crank chamber forming walls causes hindrance, it is difficult to apply and press a sealing material from outside of the opened portion of the cylinder on the side to which the crank chamber-defining wall is connected so that the treating liquid is apt to leak due to incomplete seal. When the treating liquid leaks out of the cylinder, there arise various adverse influences. In particular, when the plating liquid leaks in the plating treatment step, the treatment performance and quality of the plating are adversely affected and, at the same time, deposition of the plating liquid on the outside of the cylinder is caused. This is also undesirable from the standpoint of safety. With the foregoing circumstances in view, it is an object of the present invention to provide a surface treatment device which permits a high speed treatment, such as plating, of an inside surface of a cylindrical portion of a cylinder or the like body by allowing a treating liquid to flow, which allows the treating liquid to flow in the inside of the cylindrical portion in a satisfactory manner, which can prevent the leakage of the treating liquid from the inside of the cylindrical portion and which can perform an effective, high speed surface treatment. According to the present invention, said objective is performed by a surface treatment device as indicated in claim 1 according to which the said treating liquid feeding path is connected to a treating liquid feeding pipe for feeding the treating liquid from a tank said treating liquid discharging path is connected to a treating liquid recovering pipe for collecting the treating liquid in said tank and that said treating liquid recovering pipe is provided with a suction device for sucking said treating liquid. In the device of the present invention it is preferred that a cover member be provided for covering the upper opened portion of said cylindrical portion of said work. Further, it is preferred said cover member is provided with a washing water spraying means connected to washing water feeding means for spraying the washing water toward the inside of the cylindrical portion of said work. According to another preferred embodiment of the present invention a treating liquid feeding pump is disposed in said treating liquid feeding pipe so that said treating liquid is pressurised and is recirculated by said treating liquid feeding pump from said treating liquid feeding pipe through said treating liquid feeding path, fluid passage, treating liquid discharging path and treating liquid recovering pipe, while said treating liquid is sucked by said suction device. Alternatively, the device of the present invention, preferrably, is constructed such that said suction device is a pump with a high suction power provided in said treating liquid recovering pump, so that said treating liquid is sucked by said pump and is recirculated from said treatment liquid feeding pipe through said treating liquid feeding path, fluid passage, treating liquid discharging path and treating liquid recovering pipe. According to the present invention, the treating liquid fed through the treating liquid feeding pipe is allowed to pass through the treating liquid feeding path and the fluid passage in the cylindrical portion of the work to the treating liquid recovering pipe through the treating liquid discharging path, so that the the surface treatment is performed at a high speed in the state where the treating liquid is recirculated. In this case, by forcibly discharging the treating liquid in the inside of the cylindrical portion of the work by the suction device, the overflow of the treating liquid from the upper opened portion of the cylindrical portion during the operation is surely prevented. By providing a cover member for covering the upper opened portion of the cylindrical portion of the work, the overflow of the treating liquid is further surely prevented. By providing the cover member with washing water spraying means, washing water can be fed therefrom to the inside of the cylindrical portion after the completion of the surface treatment which has been performed while recirculating the treating liquid so that the washing can be efficiently performed. In one concrete treating liquid feeding and discharging flow system of the present invention, a treating liquid feeding pump is provided in the treating liquid feeding pipe for pressurizing and feeding the treating liquid while, while the treating liquid is sucked by the suction device. By this, the treating liquid is recirculated by the action of the treating liquid feeding pump while preventing the overflow of the treating liquid by the sucking action of the suction device. When a high suction power pump is disposed as the suction device in the treating liquid recovering pipe, the treating liquid is recirculated by the pump. Since no pressure is applied to the treating liquid in the passages inside of the cylindrical portion of the work, the overflow of the treating liquid is further surely prevented. Other preferred embodiments of the present invention are laid down in the further subclaims. In the following the present invention is explained in greater detail by means of several embodiments thereof in conjunction with the accompanying drawings wherein: Fig. 1 is a plan view schematically showing the whole plating treatment system to which the device of the present invention is applied. Fig. 2 is an elevational view schematically showing the plating treatment system. Fig. 3 is a view showing a piping system for a high speed plating in a plating treatment section. Fig. 4 is an elevational, vertical cross-sectional view showing one embodiment of a surface treatment device according to the present invention applied to the plating section. Fig. 5 is a vertical cross-sectional, side view of the surface treatment device. Fig. 6 is a sectional view taken on the line VI-VI in Fig. 5. Fig. 7 is a plan view showing one embodiment of a seal section provided on an upper opened portion of a supporting block. Fig. 8 is a sectional view of the seal section. Fig. 9 is a plan view shown another embodiment of a seal section provided on an upper opened portion of a supporting block. Fig. 10 is a sectional view of the seal section. Fig. 11 is a view showing another embodiment of the treating liquid feeding and discharging system. Fig. 12 is a vertical cross-sectional front view of a pretreatment section. Fig. 13 is a vertical cross-sectional side view of the pretreatment section. Fig. 14 is a vertical cross-sectional front view showing another embodiment of the pretreatment section. Fig. 15 is a vertical cross-sectional side view of the pretreatment section. Fig. 16 is a schematic elevational view showing another embodiment of the plating treatment system. Fig. 17 is a schematic elevational view showing another embodiment of a work transferring device. In this plating treatment system, treatment sections A-D for various pretreatments, a plating treatment section E and a drying section F are disposed along a plating treatment line in a disposition corresponding to the order of the operations. More particularly, a degreasing treatment section A, an alkali etching treatment section B, a mixed acid etching treatment section C, alumite treatment section D, a high speed plating treatment section E and a drying section F are arranged in this order. Also provided are a work feeding section 2 in the starting end side of the plating treatment line and a work delivery section 3 in the terminal end side of the plating treatment line. Disposed outside of the treatment line are degreasing liquid storage tank 4A, an alkali liquid storage tank 4B, a mixed acid liquid storage tank 4C, a mixed acid exhaust liquid tank 4C', an alumite liquid storage tank 4D and a plating liquid storage tank 4E. Treating liquid supply pumps 5A-5E and treating liquid supplying and discharging pipings (not shown in Figs. 1 ad 2) are provided between respective treating liquid tanks 4A-4E and the corresponding treatment sections A-E. Further, the plating treatment system is provided with rectifiers 6, an ion exchanger 7, a control panel 8, air exhaust fans 9 and a nitrogen oxide cleaner 10. A beam 11 extends above a transferring line. A plurality of work transferring devices 12 are moveably mounted along the beam 11. Each of the transferring devices 12 is provided with a chuck 13 moveable up and down and a driving device 14 for moving the chuck up and down. The transferring devices 12 are displaced along the beam 11 by a drive motor (not shown). The cylinder block 1 as the work is suspendedly supported by each of the transferring devices 12 by the grasping of a transferring jig 40 previously connected to an upper portion thereof with the chuck. Each of the treatment sections A-E is provided with not only parts which constitute the main part of the treatment device and which will be described in detail below but also position determining means and clamp means 15 for positioning and clamping the cylinder block 1 and the jig 40. Referring to Fig. 3 which depicts a piping system for high speed plating in the plating treatment section, a treating liquid feed pipe 21 and a treating liquid recovering pipe 22 are provided between a treatment device main body 30 having a work supporting portion at an upper end thereof, and a tank 4E containing a treating liquid (plating liquid) and a pump 5E connected to the tank. The treating liquid feed pipe 21 has an upstream end connected to the pump 5E and a downstream end connected to a hereinafter described treating liquid feeding path of the treatment device main body 30. The treating liquid recovering pipe 22 has an upstream end connected to a hereinafter described treating liquid discharging path of the treatment device main body 30 and a downstream end extending to the tank 4E. The treating liquid feed pipe 21 is provided with a main automatic valve 23 and a main manual valve 24 for adjusting the feed rate of the treating liquid, and with a flow rate sensor 25 for detecting the flow rate of the treating liquid. On the other hand, the treating liquid recovering pipe 22 is provided with an ejector (suction device) 26 for forcibly sucking and recovering the treating liquid from the treatment device main body 30. In addition to the foregoing treating liquid recirculating system, there is provided a washing water feeding pipe 27 for feeding washing water to the cylinder block 1. The washing water feeding pipe 27 has a downstream end connected to the jig 40 and an upstream end connected to a source of the washing water (not shown). An automatic valve 28 is disposed in the midway of the washing water feeding pipe 27 for adjusting the flow rate of the washing water. The washing water after the washing operation is passed to the tank 4E through the piping. Thus, the tank 4E is equipped with a concentrating device to remove by evaporation of a quantity of the water corresponding to the washing water flowing into the tank. Figs. 4 and 5 illustrate a detailed structure of the plating treatment section. In these Figures, a supporting block 32 as a work supporting portion is provided on a base table 31 of the treatment device main body. The cylinder block 1 is adapted to be supported on the supporting block 32 with both opened portions of each cylinder being maintained in a predetermined, vertically oriented state. More particularly, the cylinder block 1 has a unitary structure composed of a cylinder-constituting part 1a having four cylinders 1b and a skirt-like crank case part 1c and is supported on the supporting block 32 together with the jig 40 connected to an upper end of the crank case part 1c in an inverted state as seen from the state where the cylinder block is mounted on an automobile. The supporting block 32 has a laterally (in the direction along which the cylinders are arranged) extending, treating liquid feeding path 33 at a position beneath the cylinder disposition part 1a of the cylinder block 1. The liquid feeding path 33 has both ends connected to the treating liquid feed pipe 21 (see Fig. 3). The supporting block 32 has an upper surface provided with an opening 33a, which is in fluid communication with the treating liquid feeding path 33, at a position corresponding to each of the cylinders 1b of the cylinder block 1. A sealing section 48 is provided around the periphery of the opening. Thus, in the state where the cylinder block 1 is supported on the supporting block 32, the lower side opened portion (head-side opened portion) of each of the cylinders 1b of the cylinder block 1 coincides with the corresponding opening 33a with their peripheral edges being maintained so that the gap between the upper surface of the supporting block 32 and the lower side (head side end) of the cylinder block 1 is sealed with the sealing section 48. The treatment device main body 30 is provided with an electrode 34 which also serves to function as a fluid passage constituting member at a position corresponding to each of the cylinders 1b of the cylinder block 1. Each of the electrodes 34 is formed into a cylindrical shape and is mounted on a holder 35, which in turn is mounted on the base table 31, through a mounting member 36. Each electrode 34 extends through the treating liquid feeding path 33 and protrudes upward from the corresponding opening 33a. In the state where the cylinder block 1 is supported on the supporting block 32 as described above, each of the electrodes 34 is inserted into the corresponding cylinder 1b of the cylinder block 1 so that the upper end of the electrode 34 is positioned adjacent to an upper end of a cylinder bore with a determined space being defined between the outer peripheral surface of the electrode 34 and the inside peripheral surface of the cylinder. As a consequence, fluid passages 37 and 38 are defined inside and outside of the electrode 34 in each of the cylinders 1b of the cylinder block 1 and are in fluid communication with each other at upper ends thereof. The outer passage 37 is in fluid communication with the treating liquid feeding path 33. Each of the holders 35 is provided with a through hole which constitutes, together with the inside space of the mounting member, a treating liquid discharging path 39 which is in fluid communication with the passage 38 formed in the electrode 34. The treating liquid discharging path 39 is connected to each of the treating liquid recovering pipe 22 (see Fig. 3) through a connecting pipe 22a. The mounting member 36, holder 35 and connecting pipe 22a are formed of an electrically conductive material and are electrically connected to the rectifier. Incidentally, the position of each of the holders 35 is required to be precisely determined in a narrow space corresponding to the disposition of the corresponding cylinder 1b of the cylinder block. Further, the electrodes 34 are required to be electrically separated from each other. Thus, as shown in Fig. 6, each of the holders 35 is shaped into an ellipse with the shorter axis being oriented in the direction along which the electrodes are arranged and with the longer axis being oriented in the direction normal to the shorter axis and has a flange 35a extending outward from each end of the longer axis side and fixed to the base table 31 by bolts. The mounting member 35 is fixedly secured to the longer axis sides of the holder by bolts. The jig 40 connected to the cylinder block 1 is provided with a plate 41 which is abutting engagement with an upper opened portion of the cylinder block 1 and with a cover member 42 at a position corresponding to each cylinder 1b of the cylinder block 1 for covering the upper opened portion of the cylinder 1b. The cover member 42 is formed of a rubber, etc. shaped in an arcuate form and is mounted on the plate 41 through a bracket 43. The peripheral edge of the cover member 42 is in close contact with the inside wall of the crank case portion 1c and with the wall surface of the crankshaft supporting wall 1d disposed between the cylinders. Connected to the cover member 42 is a shower nozzle (washing water spraying means) 44 for spraying the washing water into the inside of the cylinder. The shower nozzle 44 is connected to the above-mentioned washing water feeding pipe 27 (see Fig. 3). The jig 40 is further provided with a sensor 45 extending into the cover 42 and serving as a safety device for preventing the overflow of the treating liquid. The seal section 48 between the upper surface of the supporting block 32 and the lower end of the cylinder block 1 may be constructed as shown, for example, in the structure shown in Figs. 7 and 8 or the structure shown in Figs. 9 and 10. In the embodiment shown in Figs. 7 and 8, a recessed portion 482 of a stepped state is formed around the periphery of each opened portion 33a of the supporting block 32. A seal member 481 formed from a predetermined number of interconnected, annular, flat packings is fitted into the recessed portion 482 to form the seal section 48. By the engagement of the seal member 481 with the lower end surface of the cylinder block 1, the leakage of the treating liquid is prevented and, at the same time, the deposition of the treating liquid on the lower end surface of the cylinder block 1 is prevented. In the embodiment shown in Figs. 9 and 10, a seal member formed from a predetermined number of interconnected O-rings is fitted into an annular groove 484 formed around each of the opened portion 33a on the upper side of the supporting block 32 to form the seal section 48. By the engagement of the seal member 483 and the upper surface of the supporting block 32 in the vicinity of the opened portion 33a with the lower end surface of the cylinder block 1, the leakage of the treating liquid is prevented and, at the same time, the deposition of the treating liquid on the lower end surface of the cylinder block 1 is prevented. Next, the surface treatment with the device of the present embodiment will be described. In a state where the cylinder block 1 and the jig 40 are connected to each other with the cover member 42 being disposed to cover the upper opened portion of each of the cylinders 1b, the assembly is set on the supporting block 32 of the treatment device main body 30. Thereafter, the plating liquid is fed and recirculated according to the piping system shown in Fig. 3. At the same time, the electrode 34 shown in Figs. 4 and 5 is energized to effect a high speed plating on the interior surface of each of the cylinders 1b of the cylinder block 1. That is, the plating liquid is fed from the treating liquid feeding pipe 21 to the treating liquid feeding path 33 in the supporting block 32 and is then passed, as shown by the arrow in Fig. 5, through the passage 37 defined between the electrode outer periphery 34 and the cylinder inside surface to the passage 38 of inside of the electrode 34 via the upper space of the cylinder 1b. By the suction force of the ejector 26 provided in the treating liquid recovering pipe 22, the plating liquid is forcibly sucked into the treating liquid recovering pipe 22 through the passage 38 and the treating liquid discharge path 39 and is returned to the treating liquid tank 4E. While the plating liquid is recirculated in this manner, the plating liquid flows within the cylinder along the inside peripheral surface to be plated of the cylinder. In this case, by impressing a voltage between the electrode 34 and the inside peripheral surface of the cylinder, a high speed plating is effected. In this case, since the plating liquid introduced into the upper space of the cylinder 1 from the passage 37 connected to the treating liquid feeding path 33 is forcibly sucked by the suction force of the ejector 26 into the passage 38 connected to the treating liquid discharge path, the overflow of the plating liquid from the upper opened portion of the cylinder 1b is surely prevented. Further, the cover member 42 covering the upper opened portion of the cylinder 1b prevents the scattering of the plating liquid. Since the plating liquid is sucked in the recovering side so that the plating liquid is prevented from filling the space inside of the cover member 42, the cover member 42 need not possess a perfect sealing function. It is thus sufficient that the cover member merely cover the upper opened portion of the cylinder 1b. When the ejector 26 or the like part is in trouble, the cover member serves to prevent the overflow of the plating liquid. At the same time, based on the detection by the liquid level sensor 45 of the increase of the liquid level, the pump 5E will stop operating, thereby to ensure safety. In the manner described above, the high speed plating treatment can be performed satisfactorily. After the plating treatment, washing with water is generally done. According to the device of the present embodiment, the washing operation can be performed in the plating treatment section E following the plating treatment. That is, after the completion of the plating treatment, the pump 5E and the ejector 26 stop operating. Then, the washing water is fed through the washing water feeding pipe 27 from the source of the washing liquid (not shown) and is sprayed through the shower nozzle 44 mounted on the cover member 42 into the inside of the cylinder 1b. By this operation, the interior surface of the cylinder is washed. The washing water used is passed through the treating liquid feeding pipe 21 and the treating liquid recovering pipe 22 to the treating liquid tank 4E. The concentration of the treating liquid in the treating liquid tank 4E is maintained constant by removing water by evaporation by the concentrating device during the washing operation and by spraying the washing liquid into the cylinder in the same amount as the removed amount. When the washing with water is performed in the same place as the plating treatment, the washing can be efficiently performed following the plating treatment and the space required for disposing a washing vessel is omitted, so that the total line can be made compact. In the conventional device, the washing with water is performed by displacing the work successively through a plurality of washing vessels are disposed separately from the plating treatment section. Fig. 11 depicts another embodiment of the treating liquid feeding and discharging system. In this embodiment, a self-feeding type pump 66 having a high suction power is used as a suction device disposed in the treating liquid recovering pipe 62. The embodiment is constructed such that the recirculation of the treating liquid is performed by the pump 66. Thus, in Fig. 11, the treating liquid recovering pipe connected to the treating liquid discharging path 39 of the treatment device main body 30 is gathered and the down stream end thereof is led to the tank 4E. In the treating liquid recovering pipe 62, there are disposed a flow rate controlling valve 67 and the self-feeding type pump 66 having a high section power. In the treating liquid feeding pipe 61 extending between the tank 4E and the treating liquid feeding path 33 of the treatment device main body 30, on the other hand, there are disposed a automatic valve 63, a manual valve 64 and a flow meter 65. No pump is disposed on the side of the treating liquid feeding path. A by-path 68 having a by-path automatic valve 69 extends between the treating liquid feeding pipe 61 and a portion of the treating liquid recovering pipe 62 upstream of the pump 66. According to the above treating liquid feeding and discharging system, the treating liquid is sucked by the suction force of the pump 66 through the treating liquid discharging path 39. The suction force extends to the flow passages 37 and 38, the treating liquid feeding path 33 and the treating liquid feeding pipe 61 so that, in this embodiment, too, the treating liquid is recirculated in a suitable manner. In particular, since no pressure is applied to the treating liquid in the flow passages 37 and 38, the overflow of the plating liquid from the upper opened portion of the cylinder 1b is further surely prevented. While there is a possibility that a leakage of the liquid occurs in a piping system in which the treating liquid is recirculated by pressing with a pump on the side of the treating liquid feeding pipe, leakage of liquid in the piping is surely prevented by recirculating the treating liquid by means of a suction pump 66 according to this embodiment. Further, the provision of the by-path passage 68 and the automatic valve 69 makes it possible to quickly stop the feed and discharge of the treating liquid to and from the treatment device main body 30 by opening the automatic valve 69 to permit the treating liquid to flow through the by-path passage 68 when the plating treatment is stopped. In each of the pretreatment sections of the plating treatment system shown in Figs. 1 and 2, the piping system and the treatment device main body may be constructed according to the plating treatment section. Namely, the piping system for the feeding and discharging of the treating liquid for the pretreating section may be approximately the same as that shown in Fig. 3 (or in Fig. 11). The treatment device main body of the pretreatment section may be constructed, for example, as shown in Figs. 12 and 13. In these Figures, designated as 52 is a supporting block 52 provided on a base plate 51 of a treatment device main body 50 and constructed in the same manner as the supporting block 32. The supporting block 52 has a treating liquid feeding path 53 connected to a treating liquid feeding pipe (not shown) . A cylindrical fluid passage constituting member 54 is disposed at a position corresponding to each of the cylinders 1b of the cylinder block 1. The fluid passage constituting member 54 has nearly the same shape and arrangement with the electrode 34 of the plating treatment section E and protrudes through the treating liquid feeding path 53 upward above an opening 53a. In the sate where the cylinder block 1 is supported on the supporting block 52, the fluid passage constituting member 54 is inserted into each of the cylinders 1b to form passages 57 and 58 in the outside and inside of the fluid passage constituting member 54. The lower end of the fluid passage constituting member 54 is fixed to the base table 51. The base table 51 is provided with a treating liquid discharging path 59 which includes a port 59a which is in fluid communication with the fluid passage 58 in the inside of each of the fluid passage constituting members 54, a communication passage 59b which is in fluid communication with the corresponding port 59a, and an outlet passage 59c which is in fluid communication with the communication passage 59b and extends downward. A treating liquid recovering pipe 22' is connected to the treating liquid discharging path 59. When the treatment is performed in the pretreatment section with the thus constructed treatment device main body 50, the cylinder block 1 is previously connected to the jig 40. In the state where the upper opened portion of each of the cylinders 1b is covered with the cover member 42, the cylinder block 1 and the jig 40 are supported on the supporting block 52. Then, the treating liquid which has been supplied by a pump (not shown) to the treating liquid feeding path 53 through the treating liquid feeding pipe is allowed to pass through the fluid passages 57 and 58 constituted from the fluid passage constituting member 54 in each of the cylinders of the cylinder block 1, thereby establish a flow of the treating liquid along the inside peripheral surface of the cylinder. By this, various pretreatments can be carried out at a high speed. After the treatment, the shower nozzle 44 mounted on the cover member 42 supplies a spray of the washing water to the inside of the cylinder 1b to effect washing. Thus, in the pretreatment section, too, the washing with water can be efficiently performed while saving a space for washing vessels. Accordingly, as the whole operation of the plating treating system, the cylinder block 1, in the state connected to the jig 40, is first conveyed from the work feeding section 2 to the degreasing treatment section A by the transfer device 12 and is placed on the work supporting portion of the degreasing treatment section A. After separation from the transfer device 12, the degreasing treatment is performed and washing with water is also performed there. Thereafter, the cylinder block 1 is held by the transfer device 12 and is transferred to the alkali-etching treatment section B. By repeating such operations, the treatment in the pretreatment sections A-D, treatment in the plating treating section E, washing with water and drying are successively performed. Because the demand for the prevention of the leakage of the treating liquid is especially great in the plating treatment section, the device of the present invention is applied at least to the plating treatment section. In the pretreatment section, however, the device of the present invention may be partly modified. For example, the piping system for feeding and discharging the treating liquid in the pretreatment section may be constructed such that the ejector is omitted from the piping system shown in Fig. 3. In the above-described embodiment, the cover member 42 is previously mounted on the transferring jig 40. In the pretreatment section, however, the cover member may be omitted. This may be done by constructing the cover member in a detachable state as shown in Figs. 14 and 15. Namely, in these Figures, upper opened portions of each of the cylinders 1a of the cylinder block 1 has no cover member, though the structure of the treatment device main body 30 is the same as that in Figs. 12 and 13. The treating liquid fed to the treating liquid feeding path 53 by the treating liquid feeding pump is passed, as shown by the arrow, through the fluid passage between the fluid passage constituting member 54 and the interior surface of the cylinder and overflows from the upper end of the fluid passage constituting member into the fluid passage 58 and, thereafter, is discharged to the treating liquid recovering side via treating liquid discharging path. By the action of the valves 23 and 24 (see Fig. 3) provided in the treating liquid feeding and discharging system, the feed rate of the treating liquid is controlled to adjust the amount of the overflowing liquid in an adequate range. With the above construction, too, the pretreatment may be uniformly performed at a high speed by the recirculation of the treating liquid. The construction is made simple. By the control of the treating liquid feeding rate, the overflowing amount is suitably adjusted, so that the amount of the treating liquid which deposits on portions other than the necessary portion (crankcase portion) may be minimized by permitting the overflowing liquid from the fluid passage 57 to immediately flow in the fluid passage 58. Further, the treating liquid is prevented from flowing outside. Besides, the concrete structure of the plating treatment system and the surface treatment device may be changed in various ways. For example, while, in the embodiment shown in Figs. 1-13, the transferring jig 40 equipped with the cover member 42 and the washing water spraying means is mounted on the cylinder block 1, the jig 40 and the washing water spraying means may be omitted by using a work transferring device 80 as shown in Fig. 17 which is described hereinafter, with the cover member 40 being attached to the cylinder block 1 by suitable mounting means. If desired, the cover member may be removed. As the plating system, washing sections Ga-Ge each including a recovering vessel 71 and a washing vessel 72 may be disposed between respective adjacent treatment sections A-E and between the plating treatment section E and the drying section. Fig. 17 depict an embodiment of the work transferring device capable of transferring the work without use of a transferring jig. The work transferring device 80 shown in this Figure as a whole is moveable along the transferring line and has a frame 82 vertically moveably supported on a supporting section 81. A pair of left and light chuck mechanisms 83A and 83B are mounted on the frame 82. The chuck mechanisms 83A and 83B have work shucks 84A and 84B capable of protruding and retracting at the opposing sides of the frame 82 and air cylinders 85A and 85B for driving the work chucks 84A and 84B, respectively, for clamping. By operation of the air cylinders 85A and 85B, the cylinder block 1 is clamped from both sides with the work chucks 84A and 84B. The chuck mechanisms 83A and 83B are each rotatably mounted on the frame 82 and are rotatable through an angle of 180 degrees by operation of an air cylinder 86 through a rack and a pinion (not shown). The frame 82 is moveable up and down by an air cylinder 87. With the above work transferring device 80, the work (cylinder block 1) is directly clamped by the chuck mechanisms 83A and 83B, the work is able to be displaced without using a transferring jig. This also enables to omit a station and operation for the mounting and dismounting of the work to and from the transferring jig. Thus, the cylinder block 1 is transferred by the work transferring device 80 through the surface treatment devices in the pretreatment and plating sections and through the recovering and washing vessels 71 and 72 disposed between adjacent treatment sections. In the recovering and washing vessels 71 and 72, for example, the cylinder block is delivered between a work supporting section (not shown) moveably mounted up and down to the vessels and the work transferring device 80. When the cylinder block 1 has a complicated shape, the amount of water taken from the vessels 71 and 72 tends to increase. In this case, by driving the air cylinder 86 to rotate the cylinder block 1 and the chuck mechanisms 83A and 83B clamping same therebetween through 180 degrees, the water contained in the cylinder block may be returned to the vessels 71 and 72, to thereby minimizing the loss of water. As described in the foregoing, since the surface treatment device according to the present invention includes a treatment device main body in which a work is supported such that opened portions of both sides of a cylindrical portion thereof are vertically oriented, a fluid passage constituting member providing a fluid passage for a treating liquid in the inside of the cylindrical portion of the work, treating liquid feeding and discharging paths in communication with the fluid passage, and a treating liquid recovering pipe provided with a suction device for sucking the treating liquid and disposed in the treating liquid discharging path, the surface treatment can be performed at a high speed by permitting the treating liquid to flow inside of the cylindrical portion. In this case, the flow of the treating liquid is made satisfactorily by the fluid passage defined in the cylindrical portion. Further, by forcibly discharging the treating liquid in the inside of the cylindrical portion of the work by the suction device, the overflow of the treating liquid from the upper opened portion of the cylindrical portion during the operation is surely prevented, while effectively performing the high speed surface treatment.

Claims: A surface treatment device for performing a plating treatment by feeding a treating liquid to an inside peripheral surface of a cylindrical portion (1b) of a work (1), wherein a treatment device main body (30) disposed in a work treatment section includes a work supporting portion (32) for supporting said work (1) in such a predetermined position that opened portions of both sides of said cylindrical portion are vertically oriented, comprising a fluid passage constituting member (34) providing a fluid passage for said treating liquid in the inside of said cylindrical portion of said work (1) maintained in a supported state, a treating liquid feeding path (33) in communication with the treating liquid feeding side of said fluid passage, and a treating liquid discharging path (39) in fluid communication with the treating liquid discharging side of said fluid passage, wherein said treating liquid feeding path (33) is connected to a treating liquid feeding pipe (21, 61) for feeding the treating liquid from a tank (4E), said treating liquid discharging path (39) is connected to a treating liquid recovering pipe (22, 62) for collecting the treating liquid in said tank (4E), and that said treating liquid recovering pipe (22, 62) is provided with a suction device (26, 66) for sucking said treating liquid, characterized in that said fluid passage constituting member (34) mounted on a holder is formed into a cylindrical shape protruding upwards into the cylindrical portion (1b) of the work (1) so that an upper end of the fluid passage constituting member (34) is positioned adjacent to an upper end of the cylindrical portion (1b) with a predetermined annular space being left between the outer peripheral surface of the fluid passage constituting member (34) and the inside peripheral surface of the cylindrical portion (1b) to be treated, said fluid passage constituting member (34) defining passages (37, 38) inside and outside of the fluid passage constituting member (34) which are in fluid communication at their upper ends, wherein the outer passage (37) is in fluid communication with the treating liquid feeding path (33) while the inner passage (38) formed in the fluid passage constituting member (34) is in fluid communication with the treating liquid discharging path (39). A surface treatment device as claimed in claim 1, characterized in that a cover member (42) is provided for covering an upper opened portion of said cylindrical portion (1b) of said work (1). A surface treatment device as claimed in claim 2, characterized in that said cover member (42) is provided with a washing water spraying means (44) connected to washing water feeding means (27) for spraying the washing water toward the inside of the cylindrical portion (1b) of said work (1). A surface treatment device as claimed in at least one of the claims 1 to 3, characterized in that a treating liquid feeding pump (5E) is provided in said treating liquid feeding pipe (21) so that said treating liquid is pressurized and is recirculated by said treating liquid feeding pump (5E) from said treating liquid feeding pipe (21) through said treating liquid feeding path (33), treating liquid discharging path (39) and treating liquid recovering pipe (22) while said treating liquid is sucked by said suction device (22). A surface treatment device as claimed in at least one of the preceding claims 1 to 4, characterized in that the treating liquid feed pipe (21) is provided with a main automatic valve (23) and/or a main manual valve (24) and a flow rate sensor (25) for adjusting a feed rate and detecting a flow rate of the treating liquid. A surface treatment device as claimed in at least one of the preceding claims 1 to 5, characterized in that said suction device disposed in the treating liquid recovering pipe (22) is an ejector (26) for forcibly sucking and recovering the treating liquid from the treatment device main body (30). A surface treatment device as claimed in at least one of the preceding claims 1 to 6, characterized in that the tank (4E) is equipped with a concentrating device to remove by evaporation a quantity of water corresponding to the washing water flowing into the tank (4E) during a washing operation. A surface treatment device as claimed in at least one of the preceding claims 1 to 7, characterized in that the fluid passage constituting member is an electrode (34). A surface treatment device as claimed in at least one of the preceding claims 1 to 8, characterized in that seal sections (48) are provided between a lower portion of the work (1) and the work supporting portion (32). A surface treatment device as claimed in at least one of the preceding claim 1 to 9, characterized in that said suction device is a pump (66) with a high sucking power disposed in said treating liquid recovering pipe (62), so that said treating liquid is sucked by said pump (66) and is recirculated from said treating liquid feeding pipe (61) through said treating liquid feeding path (33), fluid passage, treating liquid discharging path (39) and treating liquid recovering pipe (62).

Inventors: HIROHIKO IKEGAYA, MASAAKI ISOBE, MASAYUKI WATANABE, HIROHIKO, IKEGAYA, MASAAKI, ISOBE, MASAYUKI, WATANABE
Applicants: YAMAHA MOTOR CO LTD, YAMAHA HATSUDOKI KABUSHIKI KAISHA
Application year: 1994
Main classification: C25D5
IPC codes: C25D17, C25D7, C25D5